The present invention relates to a machine for automatically processing and inserting electronic components into a printed circuit board. More particularly, the invention relates to supply apparatus of such a machine, which selects a predetermined electronic component web carrier from a plurality of electronic component web carriers, separates electronic components individually from the electronic component web carrier, grips them and transfers them to a subsequent transfer device for transferring electronic components to inserting heads.
In the conventional technique of automatically inserting electronic components into a printed circuit board, when it is necessary to insert different kinds of electronic components into one printed circuit board, one inserting machine is used for one type of electronic components. Accordingly, if many types of electronic components are inserted, many inserting machines are used, so that the cost of equipment and operation are increased. Furthermore, the equipment requires a large space and the productivity is inevitably low.
In order to overcome the aforedescribed disadvantages, a method has been proposed in which a band-like electronic component web carrier includes different types of electronic components arranged in a predetermined order. The electronic components are separated from the web carrier and inserted into a printed circuit board one by one from one end of the web carrier. This method is, however, defective and disadvantageous, since different electronic component web carriers including electronic components arranged in a particular manner should be formed for different types of printed circuit boards, respectively, and should be stored individually. Accordingly, this method creates problems and difficulties in the manufacture and maintenance of electronic component web carriers. Furthermore, even when one of the electronic components of an electronic component web carrier has to be changed, for example, when the type of electronic component is changed because of a change in design or when an electronic component or its lead is damaged during transportation, storage or handling and should be replaced by a new one, the previously prepared electronic component web carrier having a specific arrangement of electronic components should be re-arranged. The method thus involves various difficulties and disadvantages from an industrial viewpoint.
A method has also been proposed in which a plurality of types of electronic component web carriers, each including one specific type of electronic component, are prepared. Predetermined electronic components are separated at their lead portions, one by one, according to a program. The separated electronic components are transferred by a chute in the free state to an inserting mechanism and are inserted into a printed circuit board, as disclosed in the specification of U.S. Pat. No. 3,777,350. In this method, however, leads are often damaged during the transfer and the precision of the distance or space between parallel leads is low, so that the inserting operation cannot be performed smoothly or efficiently.
The inventors have previously proposed an automatic inserting machine capable of eliminating the aforedescribed defects and disadvantages involved in the conventional techniques in U.S. Pat. No. 4,054,988 (DT-OS No. 2,614,002).